The diagnosis and treatment of breast cancer has a significant and enduring impact not only on the patient, but also on the patient's spouse or partner, and the couple's relationship as well. Breast cancer frequently leads to emotional distress for both the patient and partner, disturbances in the patient's body image, role functioning, and sexual functioning, and maladaptive patterns of interaction between the patient and partner, all of which impact both the patient's adjustment and the couple's relationship functioning. The ultimate goal of our research is to help couples in which one partner has cancer improve their ability to assist each other, both to address areas of concern and to maximize positive aspects of life. The proposed study evaluates the efficacy of a newly developed, cognitive-behavioral couple-based intervention entitled CanThrive. 292 women recently diagnosed with early stage breast cancer and their partners will be randomly assigned to one of three conditions: (1) CanThrive, which teaches couples well-validated specific relationship skills to improve their ability to communicate effectively and problem-solve about cancer-related issues, maintain satisfactory sexual functioning, and maximize positive interactions; (2) Cancer Education which provides couples with information about breast cancer and its treatment; or (3) Treatment-As-Usual, in which couples receive no active intervention. Assessment conducted before and after treatment and at 6 and 12 months follow-up includes patients' reports of communication with the husband, support from the husband, sexual adjustment and self-schema, benefit finding, mood and emotional well being, social role functioning, pain, fatigue, and physical well being; and husbands' ratings of communication with the patient, support from the patient, sexual functioning, benefit finding, mood, and psychological well being. Patients also complete daily diaries regarding perceived partner support, mood, symptoms, and role function. Also at each evaluation, couples engage in three videotaped cancer-related conversations that will be rated on dimensions of partner support and communication skills. This study may lead to major advances in our understanding of the role of relationship skills and partner involvement in the adjustment of cancer patients. If successful, it will enlarge our repertoire of methods for effectively enhancing the well being of both cancer patients and their partners.